1. Field
The inventive concepts relate to the manufacturing of semiconductor devices having layers of patterns. In particular, the inventive concepts relate to a semiconductor device having layers of patterns and overlay marking for use in determining a degree to which the layers of patterns have been properly formed relative to one another, and to the manufacturing of such a semiconductor device.
2. Description of the Related Art
The manufacturing of semiconductor devices has become very sophisticated to meet a demand for increasing the degree of integration of the semiconductor devices. Processes in the manufacturing of semiconductor devices which have become increasingly important and sophisticated include a photolithography process used to form fine patterns of a semiconductor device, an alignment process of aligning a substrate with apparatus used to perform the photolithography process, and an overlay inspection process of inspecting the relative positioning of layers of patterns formed by photolithography. The overlay inspection process may be carried out using overlay marking formed on the substrate with the photolithography equipment after a pattern of the semiconductor device has been formed. The overlay marking may comprise a diffraction grating. Light shown onto the substrate through the overlay marking may be diffracted by the diffraction grating of the overlay marking, captured, and analyzed. The overlay marking may extend in a scribe lane bordering a chip region in which the circuit patterns has been formed so that the light diffracted by the overlay pattern and captured for analysis is not adversely affected by the circuit pattern. However, a step difference between the chip region and the scribe lane may render the overlay inspection process inaccurate.